Will summer heat kill COVID-19 virus? Some trends, but experts still advise caution

GS Paper III

Topic: science and technology

Mains: Probable reasons for the fewer cases of COVID-19 in the tropics

What’s the News?

  • It was claimed that summer heat will kill COVID-19 virus however the temperature in several parts of India has crossed 30°C and is expected to touch 40°C in the northern regions in the next two weeks and it still persists.
  • There are also fewer cases found in tropical countries having high temperature across the year.
  • So the effect of temperature and humidity on the virus is still being researched worldwide.

Experts’ opinion:

  • WHO: The World Health Organization has said that from the “evidence so far, the COVID19 virus can be transmitted in ALL AREAS, including hot and humid weathers”.
  • ICMR: Indian Council of Medical Research director general Balram Bhargava has stressed that at present, there is no relationship between temperature and the spread.

However AIIMS director differ on it—

AIIMS Director Randeep Guleria: The virus probably will not survive for a long duration in an outdoor environment, if the temperature is above 40°.

Reasons behind:

  • We are still having outbreaks in (tropical) areas.
  • A lot of us spend time indoors, where the temperature is air-conditioned. Therefore, summer may help in preventing the transmission outside but possibly not indoors.

Research projection:

  • Researchers at the University of Maryland School of Medicine used weather modelling data to predict that COVID-19 is likely to follow a seasonal pattern.
  • A significant community spread along a east-west distribution approximately between latitudes 30°N and 50°N at similar weather patterns
  • These include Wuhan, South Korea, Japan, Iran, Northern Italy, Seattle, and Northern California and community spread is likely to reach north of the current areas at risk, the paper predicts.
  • These include Manchuria, Central Asia, the Caucuses, Eastern and Central Europe, the British Isles, Northeastern and Midwestern US, and British Columbia.
  • Italy, Iran, South Korea, New York and Washington exhibit weather patterns similar to original hotspots of Hubei and Hunan and are experiencing high COVID-19 growth and Countries with warmer humid climates such as Singapore and Malaysia had a lower growth rate.

Probable reasons for the fewer cases in the tropics

  • Due to less testing as many of the countries lack good healthcare facilities and may have not done enough testing to detect the actual spread as so far, the number of testing in several densely populated tropical countries (Brazil, India, Indonesia etc.) have been very low.
  • Human mobility between China and Europe and between China and the US is high; therefore the number of cases in these regions is high. However human mobility between China and South-East Asia is also high and therefore the lower growth rate in these countries is perplexing.
  • Sophisticated infrastructure does not exist in Malaysia, Thailand, Philippines, Cambodia and the lower growth rate in South-East Asia cannot be explained by lower human mobility with China or robust health infrastructure
  • It could also be argued that the government in these countries is taking exceptional measures to stop the spread which we also know is not true.

Conclusion:

The paper concludes that the lower counts in densely populated countries between 0-30°N (combined population almost 3 billion) may be due to natural factors that warrant investigation.